CVS commit: src/usr.bin/make

["Roland Illig" <rillig%netbsd.org@localhost>]

Module Name:    src
Committed By:   rillig
Date:           Mon Feb 15 17:44:09 UTC 2021

Modified Files:
        src/usr.bin/make: var.c

Log Message:
make: split parameters for evaluating variable expressions

The details of how variable expressions are evaluated is controlled by
several parameters: startc and endc differ for $(VAR) and ${VAR}, the
value of the expression can be interpreted as a single big word, and
when joining several words (such as with ':M' or ':S'), there may be a
custom word separator (defined with ':ts*').

The scope of half of these parameters is the whole variable expression,
the other half of the parameters are reset after each chain of indirect
modifiers.  To make this distinction obvious in the code, extract Expr
from ApplyModifiersState.  Previously, these details were hidden in how
parameters are passed and restored among ApplyModifiersIndirect and
ApplyModifiers.

The changes in the individual ApplyModifier functions are numerous but
straight-forward.  They mostly replace 'st' with 'expr'.

The changes in ApplyModifiers and ApplyModifiersIndirect are more
subtle.  The value of the expression is no longer passed around but is
stored in a fixed location, in Expr, which makes it easier to reason
about memory management.

The code in ApplyModifiers after 'cleanup' looks quite different but
preserves the existing behavior.  Expr_SetValueRefer is nothing else
than the combination of FStr_Done followed by FStr_InitRefer.  Storing
exprStatus back at the end was responsible for passing the definedness
of the expression after applying the indirect modifiers back to the
outer ApplyModifiersState.  The same effect is now achieved by having
Expr.status with a wider scope.

No functional change.


To generate a diff of this commit:
cvs rdiff -u -r1.822 -r1.823 src/usr.bin/make/var.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.